The McKenzie MethodThe McKenzie Method

An OverviewAn OverviewMechanical Diagnosis & Therapy of the Mechanical Diagnosis & Therapy of the

Spine:Spine:A Dynamic System of Examination, A Dynamic System of Examination,

Diagnosis, Intervention and PreventionDiagnosis, Intervention and Prevention

Who is Robin McKenzie?Who is Robin McKenzie?

History MDTHistory MDT

Robin McKenzieRobin McKenzie Physiotherapist from New ZealandPhysiotherapist from New Zealand Dr. CyriaxDr. Cyriax

strong influence on McKenzie's initial trainingstrong influence on McKenzie's initial training considered the framework for MDTconsidered the framework for MDT

Clinical experienceClinical experienceMr. Smith 1956 – 2 weeks of radicular sx then Mr. Smith 1956 – 2 weeks of radicular sx then serendipitous surpriseserendipitous surpriseExploration of End Of Range - some improved, Exploration of End Of Range - some improved, while others worsenedwhile others worsened

History - contHistory - cont

Over next 20 years developed approachOver next 20 years developed approach

Began teaching approach 1977 Rancho Began teaching approach 1977 Rancho Los AmigosLos Amigos

McKenzie Institute formed in 1982McKenzie Institute formed in 1982

26 branches around the world26 branches around the world

EpidemiologyEpidemiology

50-80% population experience back pain50-80% population experience back pain

Peak prevalence 40-50 years of age and tapers after thatPeak prevalence 40-50 years of age and tapers after that

Csp -Women tend to be affected more menCsp -Women tend to be affected more men

Lsp – Men tend to more affected than womenLsp – Men tend to more affected than women

First episodes of sx start in the 20’s w/ recurrency rates between 39-First episodes of sx start in the 20’s w/ recurrency rates between 39-71%71%

Majority (80-90%) of low back disorders occur at the L4/5 and/or Majority (80-90%) of low back disorders occur at the L4/5 and/or L5/S1L5/S1

Most cervical disorders are found in the lower region with 41% Most cervical disorders are found in the lower region with 41% occurring at the C5/6 level and 33% at the C6/7 level occurring at the C5/6 level and 33% at the C6/7 level

When the nerve root is affected, 36.1% involve the C6 root (C5-6 When the nerve root is affected, 36.1% involve the C6 root (C5-6 level), 34.6% C7 (C6-7 level) and 25.2% C8 (C7-T1 level) level), 34.6% C7 (C6-7 level) and 25.2% C8 (C7-T1 level)

Quebec Task Force ReportsQuebec Task Force Reports

Spine; 1987 – Comprehensive Scientific, Spine; 1987 – Comprehensive Scientific, Multi-disciplinary InvestigationMulti-disciplinary Investigation

Most spinal disorders are non-specificMost spinal disorders are non-specific

Classify by pain patternsClassify by pain patterns

Spitzer WO. Scientific approach to the assessment and Spitzer WO. Scientific approach to the assessment and management of activity-related spinal disorders: A mono-graph management of activity-related spinal disorders: A mono-graph

for clinicians. Report of the Quebec Task Force on Spinal for clinicians. Report of the Quebec Task Force on Spinal Disorders. Spine 1987;12(7 Suppl):1-59.Disorders. Spine 1987;12(7 Suppl):1-59.

ClassClass SymptomsSymptoms

11 Pain w/o radiationPain w/o radiation

22 Pain + radiation-proximal extremityPain + radiation-proximal extremity

33 Pain + radiation- distal extremityPain + radiation- distal extremity

44 Pain + radiation + neuro signs Pain + radiation + neuro signs

55 Nerve root compression -fx, instab Nerve root compression -fx, instab

66 Nerve root compression -image, EMG Nerve root compression -image, EMG

77 Spinal stenosis Spinal stenosis

88 S/P surgery-6 months S/P surgery-6 months

99 S/P surgery->6 months S/P surgery->6 months

1010 Chronic pain syndrome Chronic pain syndrome

1111 Other dx Other dx

BIOMECHANICSBIOMECHANICS

Spinal Motion SegmentSpinal Motion Segment

Basic functioning unit of Basic functioning unit of the spinethe spine

VertebraVertebra Intervertebral discsIntervertebral discs

Annulus fibrosus – Annulus fibrosus – Functions to retain Functions to retain

nucleusnucleus Weakest posterolaterallyWeakest posterolaterally

Nucleus pulposaNucleus pulposa connecting ligamentous connecting ligamentous

and soft tissue structures. and soft tissue structures.

Analysis of segment to:Analysis of segment to: LoadLoad PositionPosition MovementMovement

Conceptual Framework:Conceptual Framework:

DISC MODELDISC MODEL

Conceptual Model - FlexionConceptual Model - FlexionZygapophyseal joint surfaces Zygapophyseal joint surfaces distract distract

inferior articular processes of the inferior articular processes of the superior vertebra glide up and superior vertebra glide up and forward upon the superior articular forward upon the superior articular surfaces of the vertebra below. surfaces of the vertebra below.

Anterior loading of the Anterior loading of the intervertebral disc occurs with intervertebral disc occurs with compression of the anterior compression of the anterior portion, with relaxation and portion, with relaxation and bulging of the outer anterior bulging of the outer anterior annular wall. annular wall. The posterior annular wall is The posterior annular wall is stretched and pulled taut. stretched and pulled taut. The nucleus distorts posteriorly. The nucleus distorts posteriorly. The vertebral canal lengthens, The vertebral canal lengthens, stretching the cord, dura and root stretching the cord, dura and root filaments and opening the filaments and opening the intervertebral foramina. intervertebral foramina.

Conceptual Model - ExtensionConceptual Model - ExtensionInferior articular processes of the Inferior articular processes of the vertebra above glides down and vertebra above glides down and backward on the superior articular backward on the superior articular surfaces of the vertebra below. surfaces of the vertebra below. Posterior loading of the Posterior loading of the intervertebral disc occurs with intervertebral disc occurs with distraction of the anterior portion distraction of the anterior portion of the annulus, which is stretched of the annulus, which is stretched and pulled taut. and pulled taut. The posterior annular wall is The posterior annular wall is relaxed and there is posterior relaxed and there is posterior bulging of the outer, posterior bulging of the outer, posterior annular wall. annular wall. The nucleus distorts anteriorly. The nucleus distorts anteriorly. The vertebral canal shortens, The vertebral canal shortens, which relaxes the cord, dura and which relaxes the cord, dura and root filaments, and reduces the root filaments, and reduces the size of the intervertebral foramina. size of the intervertebral foramina.

LiteratureLiterature

Donelson R, Aprill C, Medcalf R, Grant W. A prospective study of Donelson R, Aprill C, Medcalf R, Grant W. A prospective study of centralization of lumbar and referred pain. A predictor of centralization of lumbar and referred pain. A predictor of symptomatic discs and annular competence. Spine; 22(10):1115-22, symptomatic discs and annular competence. Spine; 22(10):1115-22, 1997.1997.

63 subjects sent for PRE SURGICAL 63 subjects sent for PRE SURGICAL Discogram w/ Gadolinium for confirmation Discogram w/ Gadolinium for confirmation of disc pre surgical diagnosis.of disc pre surgical diagnosis.

PT’s trained in MDT, did mechanical PT’s trained in MDT, did mechanical evaluation. Therapist asked to predict:evaluation. Therapist asked to predict: Is the pain discogenic?Is the pain discogenic? If discogenic then what level?If discogenic then what level? If discogenic then was nucleus contained?If discogenic then was nucleus contained? Predict what the disc fissure pattern would Predict what the disc fissure pattern would

look like.look like.

The patients then got the discogram in flexion The patients then got the discogram in flexion and extension.and extension.

Comparisons were made between the Comparisons were made between the findings of the Discography and those findings of the Discography and those predicted by the therapist.predicted by the therapist.

Predicted vs Actual Discogram ResultsPredicted vs Actual Discogram Results Discogenic?Discogenic?

%Agreement – 83.3%%Agreement – 83.3% Level?Level?

%Agreement 93%%Agreement 93% Nucleus contained or non contained?Nucleus contained or non contained?

%Agreement – 85.5%%Agreement – 85.5% Fissure Pattern?Fissure Pattern?

%Agreement rated good/excellent%Agreement rated good/excellent

ConclusionConclusion

Dynamic disc injection outcomes are reliably Dynamic disc injection outcomes are reliably predictable w/ MDT exam and the dynamic predictable w/ MDT exam and the dynamic internal disc modelinternal disc model

This strongly supports a mechanical cause – This strongly supports a mechanical cause – effect relationship between IVD dynamics and effect relationship between IVD dynamics and the symptom response patterns of centralizationthe symptom response patterns of centralization

MDT exam appears to be a dynamic, non-MDT exam appears to be a dynamic, non-invasive functional evaluation of symptomatic invasive functional evaluation of symptomatic disc pathologydisc pathology

TISSUE BASEDTISSUE BASEDPAINPAIN

MECHANISMMECHANISM

Nociception – stimulation of receptors which provide feedback for Nociception – stimulation of receptors which provide feedback for painpain

Mechanical – application of forces that contain the receptors is Mechanical – application of forces that contain the receptors is sufficient to irritate the free nerve endings (pressure, distraction, sufficient to irritate the free nerve endings (pressure, distraction, distension, abrasion, contusion, laceration)distension, abrasion, contusion, laceration)

Chemical/Thermal - chemical irritation when concentration of Chemical/Thermal - chemical irritation when concentration of chemical substances is sufficient to irritate free nerve endings.chemical substances is sufficient to irritate free nerve endings.

It is essential to identify the type of pain (chemical or mechanical) It is essential to identify the type of pain (chemical or mechanical) because this will establish the tissue state and the subsequent because this will establish the tissue state and the subsequent treatment selectiontreatment selection

Clinical ManagementClinical Management

Goal: Goal: Relieve PainRelieve Pain Restore FunctionRestore Function Prevent reoccurrencePrevent reoccurrence

ClassificationClassification

Pain of spinal origin can be classified into Pain of spinal origin can be classified into 3 syndromes.3 syndromes. Posture SyndromePosture Syndrome Dysfunction Syndrome Dysfunction Syndrome Derangement Syndrome Derangement Syndrome

Posture SyndromePosture Syndrome

Posture SyndromePosture Syndrome

End range stress on normal structuresEnd range stress on normal structures

Mechanical deformation due to prolonged Mechanical deformation due to prolonged stress stress eventuallyeventually produces pain produces pain

Dysfunction SyndromeDysfunction Syndrome

Dysfunction SyndromeDysfunction Syndrome

End range stress of End range stress of adaptivelyadaptively shortened shortened structuresstructures

Mechanical deformation Mechanical deformation immediatelyimmediately produces pain at end of rangeproduces pain at end of range

May be discogenic, zygapophyseal, May be discogenic, zygapophyseal, ligamentous, muscular, apeneurosis, etcligamentous, muscular, apeneurosis, etc

Derangement SyndromeDerangement Syndrome

Derangement SyndromeDerangement SyndromeAnatomical disruption and/or displacement Anatomical disruption and/or displacement of structuresof structures

The structures’ increased mechanical The structures’ increased mechanical deformation immediately or eventually deformation immediately or eventually produce painproduce pain

Definition of TermsDefinition of Terms

CentralizationCentralization Describes the phenomenon in which limb pain emanating from Describes the phenomenon in which limb pain emanating from

the spine is progressively abolished in a distal to proximal the spine is progressively abolished in a distal to proximal direction in response to therapeutic loading strategies , with direction in response to therapeutic loading strategies , with each progressive symptom change being retained over time. If each progressive symptom change being retained over time. If

back pain only is present this is reduced and then abolished.back pain only is present this is reduced and then abolished. PeripheralizationPeripheralization

Describes the phenomenon by which pain emanating from the Describes the phenomenon by which pain emanating from the spine spreads distally into or further into the limb as a result spine spreads distally into or further into the limb as a result loading strategies. If pain is produced in the limb, spreads loading strategies. If pain is produced in the limb, spreads distally or increases distally and remains worse the loading distally or increases distally and remains worse the loading strategy should be avoided. strategy should be avoided.

Centralization/Periperalization - contCentralization/Periperalization - cont

Def’n - contDef’n - cont

Lateral shift Lateral shift (right)(right) A lateral shift exists when the vertebra above has A lateral shift exists when the vertebra above has

laterally flexed to one side in relation to the vertebra laterally flexed to one side in relation to the vertebra below, carrying the trunk with it. (The upper trunk and below, carrying the trunk with it. (The upper trunk and shoulders are displaced to the right.) shoulders are displaced to the right.)

Contralateral and ipsilateral shift Contralateral and ipsilateral shift A contralateral shift exists when the patient's symptoms are on A contralateral shift exists when the patient's symptoms are on

one side and the shift is in the opposite direction. For instance, one side and the shift is in the opposite direction. For instance, left back pain, with / without thigh / leg pain, and upper trunk and left back pain, with / without thigh / leg pain, and upper trunk and shoulders displaced to the right. shoulders displaced to the right.

Lateral ShiftLateral Shift

Def’n - contDef’n - cont

Criteria for Relevant lateral shift (structural vs Criteria for Relevant lateral shift (structural vs habitual) habitual)

Upper body is visibly and unmistakably shifted to one side Upper body is visibly and unmistakably shifted to one side Onset of shift occurred with back pain Onset of shift occurred with back pain Patient is unable to correct shift voluntarilyPatient is unable to correct shift voluntarily If patient is able to correct shift they cannot maintain correction If patient is able to correct shift they cannot maintain correction Correction affects intensity of symptoms Correction affects intensity of symptoms Correction causes centralization or worsening of peripheral Correction causes centralization or worsening of peripheral

symptoms symptoms

Def’n - contDef’n - cont

Symptomatic responses Symptomatic responses The changes in the patient symptoms that are elicited The changes in the patient symptoms that are elicited

and recorded with the application of assessment and recorded with the application of assessment procedures, treatment procedures or in response to procedures, treatment procedures or in response to functional activities and positions.functional activities and positions.

Mechanical responses Mechanical responses The measurable changes that occur in movement The measurable changes that occur in movement

loss, dural tension, neurological function, tolerance to loss, dural tension, neurological function, tolerance to functional activities and positions, or change in tested functional activities and positions, or change in tested physical abilities.physical abilities.

Examination termsExamination terms

Terms used to determine the response to Terms used to determine the response to repeated movements, sustained positions, repeated movements, sustained positions, treatment procedures and/or functional treatment procedures and/or functional activities and positions on pain patterns in activities and positions on pain patterns in musculoskeletal disorders. musculoskeletal disorders.

These are used BEFORE, DURING and These are used BEFORE, DURING and AFTER the procedure to accurately AFTER the procedure to accurately evaluate the response.evaluate the response.

During Mechanical LoadingDuring Mechanical Loading

IncreaseIncrease Symptoms already present are increased in Symptoms already present are increased in intensity. intensity.

DecreaseDecrease Symptoms already present are decreased in Symptoms already present are decreased in intensity.intensity.

ProduceProduce Movement or loading creates symptoms that were Movement or loading creates symptoms that were not present prior to the test. not present prior to the test.

AbolishAbolish Movement or loading abolishes symptoms that were Movement or loading abolishes symptoms that were present prior the test. present prior the test.

CentralizingCentralizing Movement or loading moves the most distal pain in Movement or loading moves the most distal pain in a proximal direction. a proximal direction.

PeripheralizingPeripheralizing Movement or loading moves the pain more distally.Movement or loading moves the pain more distally.

No EffectNo Effect Movement or loading has no effect on the Movement or loading has no effect on the symptoms. symptoms.

After Mechanical LoadingAfter Mechanical Loading

WorseWorse Symptoms produced or increased with movement or Symptoms produced or increased with movement or loading remain aggravated following the test. loading remain aggravated following the test.

Not WorseNot Worse Symptoms produced or increased with movement or Symptoms produced or increased with movement or loading return to baseline after testing.loading return to baseline after testing.

BetterBetter Symptoms decreased or abolished with movement Symptoms decreased or abolished with movement or loading remain improved after testing.or loading remain improved after testing.

Not BetterNot Better Symptoms decreased or abolished with movement Symptoms decreased or abolished with movement or loading return to baseline after testing.or loading return to baseline after testing.

CentralizedCentralized Distal symptoms abolished by movement or loading Distal symptoms abolished by movement or loading remain abolished after testing.remain abolished after testing.

PeripheralizedPeripheralized Distal pain produced during movement or loading Distal pain produced during movement or loading remain after testing.remain after testing.

No EffectNo Effect Movement or loading has no effect on symptoms Movement or loading has no effect on symptoms after testing.after testing.

EVALUATION PROCESSEVALUATION PROCESSPATIENT HISTORY– 1* role is to PATIENT HISTORY– 1* role is to establish a hypothetical diagnosis establish a hypothetical diagnosis

Location of painLocation of pain Duration of current episode of painDuration of current episode of pain Intermittent or Constant painIntermittent or Constant pain MOIMOI Symptomatic and Mechanical responses to:Symptomatic and Mechanical responses to:

bending, sitting, rising from sitting, turning, lying, rising form bending, sitting, rising from sitting, turning, lying, rising form lying; upon waking, as the day progresses, in the evening, lying; upon waking, as the day progresses, in the evening, when still and when on the move when still and when on the move

How many previous episodes and similarities?How many previous episodes and similarities? RED FLAGS and possible contraindications to MDT?RED FLAGS and possible contraindications to MDT? Occupation:Occupation:

PHYSICAL EXAMINATIONPHYSICAL EXAMINATION

Primary role is to confirm hypothetical Primary role is to confirm hypothetical diagnosis from patient history along w/ diagnosis from patient history along w/ determining appropriate loading strategydetermining appropriate loading strategy

Posture:Posture: HabitsHabits Acute spinal deformity – lateral shift, Acute spinal deformity – lateral shift,

torticollis, etctorticollis, etc Other abnormalities: leg length difference, Other abnormalities: leg length difference,

scoliosis, atrophy, etcscoliosis, atrophy, etc

Physical Exam - contPhysical Exam - cont

Neuro exam as appropriateNeuro exam as appropriateMovement Loss Movement Loss

Willingness to move/quality/quantityWillingness to move/quality/quantity Baseline for determination of the mechanical response of the Baseline for determination of the mechanical response of the

test movements/positionstest movements/positions

Repeated MovementRepeated Movement Observations are made as to symptom and mechanical Observations are made as to symptom and mechanical

response after several repetitionsresponse after several repetitions

Sustained testSustained test can be performed if the repeated test movements don’t provide can be performed if the repeated test movements don’t provide

adequate information to come to a conclusion adequate information to come to a conclusion

Other – ie VBI, Hip, SIJ, Shoulder etc clearing testsOther – ie VBI, Hip, SIJ, Shoulder etc clearing tests

Test Movements – CervicalTest Movements – Cervicalaka Active Physiological aka Active Physiological

MovementsMovements

Protrusion (Pro) and Repeated (Rep Pro)Protrusion (Pro) and Repeated (Rep Pro)Retraction (Ret) and Repeated (Rep Ret)Retraction (Ret) and Repeated (Rep Ret)Retraction Extension (Ret Ext) and Repeated (Rep Ret Ext)Retraction Extension (Ret Ext) and Repeated (Rep Ret Ext)Sidebend (SB) and Repeated (Rep SB)Sidebend (SB) and Repeated (Rep SB)Rotation (Rot) and Repeated (Rep Rot)Rotation (Rot) and Repeated (Rep Rot)Flexion (Flex) and Repeated (Rep Flex)Flexion (Flex) and Repeated (Rep Flex)

ProtrusionProtrusion

RetractionRetraction

Retraction ExtensionRetraction Extension

FlexionFlexion

SidebendSidebend

RotationRotation

Derangement SyndromesDerangement Syndromes

Derangement SyndromesDerangement Syndromes

DerangementDerangement Clinical PresentationClinical Presentation

11 Central or symmetrical pain across C5-7Central or symmetrical pain across C5-7

Rarely Scap or shoulder painRarely Scap or shoulder pain

NO DEFORMITYNO DEFORMITY

Extension limitedExtension limited

Rapidly ReversibleRapidly Reversible

22 Central or symmetrical pain across C5-7Central or symmetrical pain across C5-7

W/ or W/O Scap/Sh or Upper arm painW/ or W/O Scap/Sh or Upper arm pain

KYPHOTIC DEFOMITYKYPHOTIC DEFOMITY

Rarely Rapidly reversibleRarely Rapidly reversible

Derangement SyndromesDerangement Syndromes

DerangementDerangement Clinical PresentationClinical Presentation

33 Unilat or Asymmetrical pain across C5-7Unilat or Asymmetrical pain across C5-7

w/ or w/o Scap/Sh or Upper arm painw/ or w/o Scap/Sh or Upper arm pain

NO DEFORMITYNO DEFORMITY

Ext, Rot and later flex or combo limitedExt, Rot and later flex or combo limited

Rapidly reversibleRapidly reversible

44 Unilat or Asymmetrical pain across C5-7Unilat or Asymmetrical pain across C5-7

w/ or w/o Scap/Sh or Upper arm painw/ or w/o Scap/Sh or Upper arm pain

Relavent LATERAL SHIFT or TorticollisRelavent LATERAL SHIFT or Torticollis

Ext, Rot and later flex limitedExt, Rot and later flex limited

Derangement SyndromesDerangement Syndromes

DerangementDerangement Clinical PresentationClinical Presentation

55 Unilat or Asymmetrical pain across C5-7Unilat or Asymmetrical pain across C5-7

w/ or w/o Scap/Sh or Upper arm pain w/ or w/o Scap/Sh or Upper arm pain AND w/ arm sx distal to elbowAND w/ arm sx distal to elbow

W/ Leg pain extending below kneeW/ Leg pain extending below knee

NO DEFORMITYNO DEFORMITY

Ext, ipsilateral lat flex limitedExt, ipsilateral lat flex limited

Rapidly ReversibleRapidly Reversible

66 Unilat or Asymmetrical pain across L4/5Unilat or Asymmetrical pain across L4/5

w/ or w/o Scap/Sh or Upper arm pain w/ or w/o Scap/Sh or Upper arm pain AND w/ arm sx distal to elbowAND w/ arm sx distal to elbow

Relavent LATERAL SHIFT- Csp Kyphosis Relavent LATERAL SHIFT- Csp Kyphosis or Torticollisor Torticollis

Not rapidly reversibleNot rapidly reversible

Derangement SyndromesDerangement Syndromes

DerangementDerangement Clinical PresentationClinical Presentation

77 Unilat or Asymmetrical pain across C5-7Unilat or Asymmetrical pain across C5-7

w/ or w/o Ant/Ant-lat neck painw/ or w/o Ant/Ant-lat neck pain

No deformityNo deformity

Flex limitedFlex limited

Rapidly reversibleRapidly reversible

PosturePosture DysfunctionDysfunction DerangementDerangement

AgeAge YoungerYounger 20-4020-40

PathologyPathology NoneNone Adaptively Adaptively shortened tissueshortened tissue

YesYes

Pain LocationPain Location LocalLocal Local (except ANR)Local (except ANR) Local or remoteLocal or remote

Pain ReferredPain Referred NoneNone None (except ANR)None (except ANR) PossiblePossible

DeformityDeformity NoneNone None (exceptions)None (exceptions) PossiblePossible

ROM LossROM Loss NoneNone YesYes YesYes

Rep Test Mvt: PDMRep Test Mvt: PDM NoneNone None (except ANR)None (except ANR) PossiblePossible

Rep Test Mvt: ERPRep Test Mvt: ERP NoneNone YesYes YesYes

Rep Test Mvt: EffectsRep Test Mvt: Effects NENE P, ERP, NWP, ERP, NW P/A, B/W, Incr/Decr, P/A, B/W, Incr/Decr, NB/NW, Cent/Peri NB/NW, Cent/Peri

DefinitionDefinition Normal tissue/Normal tissue/

Abnormal stressAbnormal stress

Adaptively Adaptively shortened tissue/ shortened tissue/ normal stressnormal stress

Rapid change w/ mvtRapid change w/ mvt

Mechanical displacmnt Mechanical displacmnt of motion segmentof motion segment

TreatmentTreatment Posture CorrectionPosture Correction

Posture EdPosture Ed

ProphalaxisProphalaxis

Remodel: Rep mvt Remodel: Rep mvt TOWARD direction TOWARD direction of restrictionof restriction

ProphalaxisProphalaxis

ReduceReduce

MaintainMaintain

RemodelRemodel

ProphylaxisProphylaxis

ReferencesReferencesDonelson R, Aprill C, Medcalf R, Grant W. A prospective study of centralization of Donelson R, Aprill C, Medcalf R, Grant W. A prospective study of centralization of lumbar and referred pain. A predictor of symptomatic discs and anular competence. lumbar and referred pain. A predictor of symptomatic discs and anular competence. Spine; 22(10):1115-22, 1997.Spine; 22(10):1115-22, 1997.Long A; The centralization phenomenon: its usefulness as a predictor of outcome in Long A; The centralization phenomenon: its usefulness as a predictor of outcome in conservative treatment of chronic low back pain, a pilot study. Spine; 20(23):2513-conservative treatment of chronic low back pain, a pilot study. Spine; 20(23):2513-2521, 1995.2521, 1995.Long A, Donelson R, Fung T; Does it matter which exercise? A randomized control Long A, Donelson R, Fung T; Does it matter which exercise? A randomized control trial of exercises for low back pain. Spine; Dec 1;29(23):2593-2602, 2004.trial of exercises for low back pain. Spine; Dec 1;29(23):2593-2602, 2004.McKenzie Course notes A, B, C, D, EMcKenzie Course notes A, B, C, D, EMcKenzie RA 1990. The lumbar spine: mechanical diagnosis and therapy. Spinal McKenzie RA 1990. The lumbar spine: mechanical diagnosis and therapy. Spinal Publications, New Zealand.Publications, New Zealand.McKenzie RA 1990. The cervical and thoracic spine: mechanical diagnosis and McKenzie RA 1990. The cervical and thoracic spine: mechanical diagnosis and therapy. Spinal Publications, New Zealandtherapy. Spinal Publications, New ZealandMcKenzieMDT.org McKenzieMDT.org Petty NJ 2006. Neuromusculoskeletal examination and assessment: a handbook for Petty NJ 2006. Neuromusculoskeletal examination and assessment: a handbook for therapist, 3therapist, 3rdrd ed. Elsevier Limited. ed. Elsevier Limited.Spitzer WO. Scientific approach to the assessment and management of activity-Spitzer WO. Scientific approach to the assessment and management of activity-related spinal disorders: A mono-graph for clinicians. Report of the Quebec Task related spinal disorders: A mono-graph for clinicians. Report of the Quebec Task Force on Spinal Disorders. Spine 1987;12(7 Suppl):1-59.Force on Spinal Disorders. Spine 1987;12(7 Suppl):1-59.